ya its B. 320 dynes-sec/cm5

normally we measure pressure in mmhg/l/min but if its given in dynes-sec/cm5...u just hv to multiply mmhg/l/min value with 80...

here R=P1-P2/Q

=26-10/4

=16/4

=4 mmhg/l/min...

now multiply with 80...

then its 320 dynes-sec/cm5...